This invention relates to a novel optical disc recording system for recording information on and reproducing it from a writable type optical disc, and, more particularly, to an optical disc recording system capable of playing back a recorded optical disc by utilizing a playback device adapted exclusively for playing back a standardized optical disc which is not writable such as a CD (Compact Disc), CD-ROM, CD-I (CD-Interactive), CDV (Compact Disc with video) or LV (laser vision disc) (such optical disc will hereinafter be referred to as "optical disc for playback only") and thereby obviating the necessity for using a playback device adapted exclusively for playing back the recorded disc.
As writable type optical discs, there are DRAW (direct read after write) discs and E-DRAW (erasable type DRAW) discs. DRAW discs are discs on which data can be written only once and include a type of disc on which an information pit is formed by burning off a metal recording film by heat generated by irradiation by a laser beam.
E-DRAW discs are discs on which information can be rewritten and include one utilizing a technique of photo-magnetic recording and one utilizing phase change between a crystal state and an amorphous state.
Since these prior art DRAW discs and E-DRAW discs are different from optical discs for playback only such as CD, CD-ROM, CD-I, LV discs etc. in their recording format, configuration of the disc (such as the outer diameter), revolution velocity and in other respects, the DRAW discs and E-DRAW discs cannot be played back with playback devices adapted exclusively for playing back such optical discs for playback only.
Even if the recording format, disc configuration etc. are the same as the optical discs for playback only, the E-DRAW discs using the photo-magnetic recording or phase change are low in the rate of light reflection (i.e., rate of light reflection in a mirror portion (non-grooved portion) is, for example, less than 50%) and, accordingly, such DRAW and E-DRAW discs cannot be played back with the playback devices for the optical discs for playback only.
The prior art DRAW discs in which an information pit is formed by burning off the metal film (e.g., Al, Au or the like) by irradiation by a laser beam have a sufficient rate of light reflection but they require a powerful laser device such as one using a gas laser to record information with a result that the recording device tends to become so bulky and expensive that it prohibits use of the system in devices for domestic uses.
It is, therefore, an object of the invention to eliminate the above described drawbacks of the prior art optical disc recording systems and provide an optical disc recording system capable of utilizing a playback device adapted for playing back an optical disc for playback only in playing back a recorded disc and capable of construction of the recording device cheaply and in a compact form.